When manufacturing a semiconductor device, a processing apparatus is used for cleaning, with the use of a chemical liquid, a semiconductor wafer (referred to as “wafer” below) held by a spin chuck. In a cleaning step performed by such an apparatus, a process liquid such as a deionized water is supplied to a wafer, and thereafter the wafer is rotated to remove liquid droplets therefrom due to the centrifugal force, so that the wafer is dried.
Conventional methods for drying a wafer include methods for spraying a rotating wafer with an IPA (isopropyl alcohol) vapor, spraying a rotating wafer with an atomized IPA, and supplying an IPA liquid to a rotating wafer. Another method for drying a wafer is, while supplying a deionized water to a wafer from a nozzle that radially moves outward from a rotational center of the wafer, to supply an IPA vapor to the wafer at a position nearer to the rotational center than a position at which the deionized water is supplied (JP 11-233481A and JP 2003-197590A). There has been proposed another method for drying a wafer in which, while a deionized water is supplied to a wafer, an inert gas is sprayed onto the wafer at a position nearer to a rotational center of the wafer than a position at which the deionized water is supplied (JP2001-53051A).
However, the conventional methods for drying a wafer by supplying a drying process liquid, such as IPA, are disadvantageous in that a large amount of process liquid is consumed.